Sound output device

Abstract

To provide an acoustic output device.SOLUTION: An acoustic output device may include a bone conduction speaker for generating a bone conduction sound wave. The acoustic output device may include an air conduction speaker for generating an air conduction sound wave, the air conduction speaker being independent from the bone conduction speaker. The acoustic output device may further include at least one housing for storing the bone conduction speaker and the air conduction speaker.SELECTED DRAWING: Figure 5A

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to a Chinese patent application bearing application number 202010247338.2, filed on March 31, 2020, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE INVENTION This specification relates generally to audio output devices, and more particularly to audio output devices that utilize both bone conduction and air conduction to provide audio signals to a user. [Background technology]

[0003] Currently, wearable audio output devices (e.g., earphones) are emerging and becoming increasingly popular. Open-ear audio output devices (e.g., bone conduction speakers) are portable audio devices that can facilitate sound conduction to a user. However, bone conduction speakers have poor performance in the mid-low frequency range and produce strong vibrations, which affect the user experience, especially user comfort. Therefore, it is desirable to develop an audio output device that improves a user's audio experience in the mid-low frequency range. Summary of the Invention [Means for solving the problem]

[0004] In one aspect of the present disclosure, there is provided an acoustic output device, which may include a bone conduction speaker configured to generate bone conduction sound waves, an air conduction speaker configured to generate air conduction sound waves and independent of the bone conduction speaker, and at least one housing configured to accommodate the bone conduction speaker and the air conduction speaker.

[0005] In some embodiments, the bone conduction speaker includes a vibration assembly, the vibration assembly including a magnetic circuit system configured to generate a magnetic field, a diaphragm connected to the at least one housing, and one or more coils connected to the diaphragm, vibrating in the magnetic field and driving the diaphragm to vibrate and generate the bone conduction sound waves.

[0006] In some embodiments, the air conduction speaker includes a diaphragm and a driver that drives the diaphragm to vibrate to generate the air conduction sound waves.

[0007] In some embodiments, the air conduction speaker is located next to the bone conduction speaker.

[0008] In some embodiments, the at least one housing includes a first housing and a second housing, the bone conduction speaker being housed in the first housing and the air conduction speaker being housed in the second housing.

[0009] In some embodiments, the vibration direction of the bone conduction speaker is a first direction, the central vibration direction of the diaphragm of the air conduction speaker is a second direction, and the first direction is parallel to the second direction.

[0010] In some embodiments, the distance from the air conduction speaker to the listening position is less than the distance from the bone conduction speaker to the listening position.

[0011] In some embodiments, the second housing includes an acoustic hole facing the listening position.

[0012] In some embodiments, the air conduction speaker and the bone conduction speaker are stacked.

[0013] In some embodiments, the vibration direction of the bone conduction speaker and the vibration direction of the center of the diaphragm of the air conduction speaker are the same direction.

[0014] In some embodiments, the at least one housing includes a third housing, and the bone conduction speaker and the air conduction speaker are housed within the third housing.

[0015] In some embodiments, the third housing includes a housing wall that transmits the bone-conducted acoustic waves outward.

[0016] In some embodiments, the third housing includes an acoustic hole facing the listening position.

[0017] In some embodiments, the bone conduction speaker and the air conduction speaker are arranged perpendicular to each other.

[0018] In some embodiments, the vibration direction of the bone conduction speaker is a third direction, the central vibration direction of the diaphragm of the air conduction speaker is a fourth direction, and the third direction is substantially perpendicular to the fourth direction.

[0019] In some embodiments, the at least one housing includes a fourth housing, and the bone conduction speaker and the air conduction speaker are housed within the fourth housing.

[0020] In some embodiments, the bone-conducted sound waves include mid- to high-frequency waves and the air-conducted sound waves include mid- to low-frequency waves.

[0021] In some embodiments, the bone-conducted sound waves include low to mid frequencies and the air-conducted sound waves include high to mid frequencies.

[0022] In some embodiments, the air-conducted sound waves include low and mid frequencies and the bone-conducted sound waves include frequencies within a wider frequency range than the frequencies of the air-conducted sound waves.

[0023] In some embodiments, the bone-conducted sound waves include low and mid frequencies and the air-conducted sound waves include frequencies within a wider frequency range than the frequencies of the bone-conducted sound waves.

[0024] In some embodiments, the air-conducted sound waves include mid-to-high frequencies and the bone-conducted sound waves include frequencies within a wider frequency range than the frequencies of the air-conducted sound waves.

[0025] In some embodiments, the bone-conducted sound waves include mid-to-high frequencies and the air-conducted sound waves include frequencies within a wider frequency range than the frequencies of the bone-conducted sound waves.

[0026] Additional features of the specification will be set forth in part in the description that follows. Additional features of the specification will, in part, become apparent to those skilled in the art upon examination of the following description and accompanying drawings, or may be learned by the production or operation of the embodiments. Features of the specification may be realized or learned by practice or use of various aspects of the methods, instrumentalities, and combinations of the specific embodiments described below.

[0027] This specification will further describe exemplary embodiments. These exemplary embodiments will be described in more detail with reference to the drawings. The drawings are not drawn to scale. These embodiments are not limiting, and in these embodiments, like numbers represent like structures. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a schematic diagram of an exemplary acoustic system shown in some embodiments herein. [Figure 2A] FIG. 1 is a schematic diagram of an exemplary acoustic output device in accordance with some embodiments of the present disclosure. [Figure 2B] FIG. 1 is a schematic diagram of an exemplary acoustic output device in accordance with some embodiments of the present disclosure. [Figure 3A]FIG. 1 is a schematic diagram of an exemplary acoustic output device in accordance with some embodiments of the present disclosure. [Figure 3B] FIG. 1 is a schematic diagram of another exemplary acoustic output device in accordance with some embodiments of the present disclosure. [Figure 4] FIG. 1 is a schematic diagram of a resonant system according to some embodiments of the present disclosure. [Figure 5A] 1 is a schematic diagram of an exemplary bone conduction speaker according to some embodiments of the present disclosure. [Figure 5B] FIG. 1 is a schematic diagram of an exemplary air conduction speaker according to some embodiments of the present disclosure. [Figure 6] FIG. 1 is a schematic diagram of an exemplary acoustic output device in accordance with some embodiments of the present disclosure. [Figure 7] FIG. 1 is a schematic diagram of an exemplary acoustic output device in accordance with some embodiments of the present disclosure. [Figure 8] FIG. 1 is a schematic diagram of an exemplary acoustic output device in accordance with some embodiments of the present disclosure. [Figure 9] FIG. 6 is a schematic diagram of a leakage frequency response curve of an acoustic output device 600 in accordance with certain embodiments of the present disclosure. [Figure 10] FIG. 6 is a schematic diagram of a leakage frequency response curve of an acoustic output device 600 in accordance with certain embodiments of the present disclosure. [Figure 11] FIG. 1 is a schematic diagram of an exemplary acoustic output device in accordance with some embodiments of the present disclosure. [Figure 12] FIG. 1 is a schematic diagram of an exemplary acoustic output device in accordance with some embodiments of the present disclosure. [Figure 13] FIG. 11 is a schematic diagram of a leakage frequency response curve of an acoustic output device 1100 according to some embodiments of the present disclosure. [Figure 14] FIG. 11 is a schematic diagram of a leakage frequency response curve of an acoustic output device 1100 according to some embodiments of the present disclosure. [Figure 15] FIG. 1 is a schematic diagram of an exemplary acoustic output device in accordance with some embodiments of the present disclosure. [Figure 16] FIG. 15 is a schematic diagram of a leakage frequency response curve of an acoustic output device 1500 in accordance with certain embodiments of the present disclosure. [Figure 17] FIG. 1 is a schematic diagram of a frequency response characteristic curve of an acoustic output device according to some embodiments of the present disclosure. [Figure 18] FIG. 1 is a schematic diagram of a frequency response characteristic curve of an acoustic output device according to some embodiments of the present disclosure. [Figure 19] FIG. 1 is a schematic diagram of a frequency response characteristic curve of an acoustic output device according to some embodiments of the present disclosure. [Figure 20] FIG. 1 is a schematic diagram of a frequency response characteristic curve of an acoustic output device according to some embodiments of the present disclosure. [Figure 21] FIG. 1 is a schematic diagram of a frequency response characteristic curve of an acoustic output device according to some embodiments of the present disclosure. [Figure 22] FIG. 1 is a schematic diagram of a vibration displacement spectrum of a bone conduction speaker according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0029] The following description is provided to enable those skilled in the art to implement and use the present specification, and is provided in the context of a particular application scenario and required environment. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the principles and scope of the present specification. Thus, the present specification is not intended to be limited to the embodiments described, but is to be accorded the widest scope consistent with the appended claims.

[0030] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not limiting. As used herein, the singular forms "a," "an," and "the" may include the plural unless the context clearly dictates otherwise. It will be further understood that the terms "comprise," "include," and / or "including," "comprises," "comprises," and / or "comprising," when used herein, specify the presence of stated features, integers, operations, elements, and / or assemblies, but do not exclude the presence or addition of one or more other features, integers, operations, elements, assemblies, and / or combinations thereof.

[0031] It will be understood that the terms "system," "engine," "unit," "module," and / or "block" used herein are ways of distinguishing between different levels of assemblies, elements, parts, portions, or assemblies, however, other terms can be used in place of the above terms if the same purpose is achieved.

[0032] Generally, the words “module,” “unit,” or “block” as used herein refer to logic embodied in hardware or firmware, or a collection of software instructions. The modules, units, or blocks described herein may be implemented as software and / or hardware and may be stored on any type of non-transitory computer-readable medium or other storage device. In some embodiments, software modules / units / blocks may be compiled and linked into an executable program. It will be understood that software modules may be called by other modules / units / blocks or by themselves, and / or may be called in response to detected events or interrupts. Software modules / units / blocks configured to execute on a processing device (e.g., processor 220 shown in FIG. 2) may be provided on a computer-readable medium such as an optical disk, digital video disk, flash memory drive, magnetic disk, or any other tangible medium, or may be provided as a digital download (and may be stored in a compressed or installable format and require installation, decompression, or decryption before execution). Such software code may be partially or completely stored in the storage device of the executing device for execution by the processing device. Software instructions may also be embedded in firmware, such as an EPROM. It will be understood that a hardware module / unit / block may be comprised of connected logic components such as gates and flip-flops, and / or may comprise a programmable unit such as a programmable gate array or a processor. The functionality of a module / unit / block or processing device described herein may be implemented as a software module / unit / block, but may also be represented in hardware or firmware.Generally, the modules / units / blocks described herein refer to logic modules / units / blocks that may be combined with other modules / units / blocks or divided into sub-modules / sub-units / sub-blocks, regardless of whether they are physical structures or storage devices. The description may apply to a system, engine, or part thereof.

[0033] When a unit, engine, module, or block is referred to as being "located on," "connected to," or "coupled to" another unit, engine, module, or block, it will be understood that it may be directly located on, connected to, coupled to, or in communication with the other unit, engine, module, or block, or that intermediate units, engines, modules, or blocks may be present, unless the context clearly dictates otherwise. As used herein, the term "and / or" may include any one or more of the associated listed items or combinations thereof.

[0034] In order to more clearly explain the technical solutions of the embodiments of the present specification, the drawings referred to in the description of the embodiments will be briefly described below. Obviously, the drawings described below are merely examples or parts of the embodiments of the present specification. Those skilled in the art can apply the present specification to other similar scenarios based on these drawings without any creative effort. Unless otherwise clear from the context or specified, the same symbols in the drawings represent the same structures or operations.

[0035] The technical solutions of the embodiments of this specification are described below with reference to the drawings. Obviously, the described embodiments are neither exhaustive nor limiting. Based on the embodiments provided in this specification, any other embodiments that can be obtained by those skilled in the art without any creative effort are within the scope of this specification.

[0036] One aspect of the present specification relates to an audio output device. The audio output device may include a bone conduction speaker (also called a vibration speaker), an air conduction speaker, and at least one housing configured to accommodate the bone conduction speaker and the air conduction speaker. The air conduction speaker is independent of the bone conduction speaker. By providing various spatial arrangements and / or frequency distributions of the bone conduction speaker and the air conduction speaker, it is possible to improve a user's audio experience with the audio output device at low frequencies and reduce sound leakage from the audio output device.

[0037] 1 is a schematic diagram of an exemplary audio system shown in some embodiments herein. The audio system 100 may include a multimedia platform 110, a network 120, an audio output device 130, a terminal device 140, and a storage device 150.

[0038] Multimedia platform 110 may communicate with one or more assemblies of sound system 100 or with external data sources (e.g., a cloud data center). In some embodiments, multimedia platform 110 may provide data or signals (e.g., audio data of a musical piece) to audio output device 130 and / or user terminal 140. In some embodiments, multimedia platform 110 may facilitate data / signal processing for audio output device 130 and / or user terminal 140. In some embodiments, multimedia platform 110 may be implemented on a single server or a collection of servers. The collection of servers may be a centralized collection of servers connected to network 120 via an access point, or a distributed collection of servers, each connected to network 120 via one or more access points. In some embodiments, multimedia platform 110 may be locally connected to network 120 or remotely connected to network 120. For example, multimedia platform 110 may access information and / or data stored in audio output device 130, user terminal 140, and / or storage device 150 via network 120. Also for example, storage device 150 may be used as a back-end data storage device for multimedia platform 110. In some embodiments, multimedia platform 110 may be implemented on a cloud platform. By way of example only, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-cloud, etc., or any combination thereof.

[0039] In some embodiments, multimedia platform 110 may include processing unit 112. Processing unit 112 may perform the primary functions of multimedia platform 110. For example, processing unit 112 may retrieve audio data from storage unit 150 and transmit the retrieved audio data to acoustic output device 130 and / or user terminal 140 to generate sound. Also, for example, processing unit 112 may process signals for acoustic output device 130 (e.g., to generate bone conduction control signals).

[0040] In some embodiments, processing unit 112 may include one or more processing units (e.g., a single-core processing unit or a multi-core processing unit). By way of example only, processing unit 112 may include a central processing unit (CPU), an application specific integrated circuit (ASIC), an application specific instruction set processor (ASIP), a graphics processing unit (GPU), a physical processing unit (PPU), a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a controller, a microcontroller unit, a reduced instruction set computer (RISC), a microprocessor, etc., or any combination thereof.

[0041] Network 120 can facilitate the exchange of information and / or data. In some embodiments, one or more assemblies in sound system 100 (e.g., multimedia platform 110, audio output device 130, user terminal 140, and storage device 150) may transmit information and / or data to other assemblies in sound system 100 via network 120. In some embodiments, network 120 may be any type of wired or wireless network, or a combination thereof. By way of example only, network 120 may include a cable network, a wired network, an optical fiber network, a telecommunications network, an intranet, the Internet, a local area network (LAN), a wide area network (WAN), a wireless local area network (WLAN), a metropolitan area network (MAN), a public switched telephone network (PSTN), a Bluetooth network, a ZigBee network, a near field communication (NFC) network, etc., or any combination thereof. In some embodiments, network 120 may include one or more network access points. For example, network 120 may include wired or wireless network access points, such as base stations and / or Internet switching points, by which one or more assemblies of sound system 100 can be connected to network 120 to exchange data and / or information.

[0042] The audio output device 130 can output audio to and interact with a user. On the one hand, the audio output device 130 can provide the user with audio content such as at least songs, poetry, news broadcasts, weather broadcasts, audio lessons, etc. On the other hand, the user can provide feedback to the audio output device 130 through keys, screen touches, body movements, voice, gestures, awareness, etc. In some embodiments, the audio output device 130 can be a wearable device. Unless otherwise stated, the term "wearable device" as used herein can include earphones and various other types of personal devices such as head-worn, shoulder-worn, or body-worn devices. The wearable device can provide at least audio content to the user with or without contact with the user. In some embodiments, the wearable device can include smart earphones, smart glasses, a head-mounted display (HMD), a smart bracelet, smart footwear, smart glasses, a smart helmet, a smart watch, smart clothing, a smart backpack, a smart accessory, a virtual reality helmet, virtual reality glasses, a virtual reality patch, an augmented reality helmet, augmented reality glasses, an augmented reality patch, etc., or any combination thereof. As an example only, a wearable device may be Google Glass. TM , Oculus Rift TM , Hololens TM , Gear VR TM It may be similar to the above.

[0043] The audio output device 130 may communicate with the user terminal 140 via the network 120. In some embodiments, various types of data and / or information may be received by the audio output device 130, such as movement parameters (e.g., geographic location, movement direction, movement speed, acceleration, etc.), audio parameters (audio volume, audio content, etc.), gestures (e.g., handshake, head shake, etc.), user consciousness, etc. In some embodiments, the audio output device 130 may further transmit the received data and / or information to the multimedia platform 110 or the user terminal 140.

[0044] In some embodiments, the user terminal 140 may be customized, for example, to communicate with the audio output device 130 and / or perform data / signal processing via an application program installed on the user terminal. The user terminal 140 may include a mobile device 130-1, a tablet computer 130-2, a laptop computer 130-3, an in-vehicle built-in device 130-4, etc., or any combination thereof. In some embodiments, the mobile device 130-1 may include a smart home device, a smart mobile device, or similar devices, or any combination thereof. In some embodiments, the smart home device may include a smart lighting device, a smart appliance control device, a smart monitoring device, a smart television, a smart video camera, an intercom, etc., or any combination thereof. In some embodiments, the smart mobile device may include a smartphone, a personal digital assistant (PDA), a gaming device, a navigation device, a point-of-sale device (POS), etc., or any combination thereof. In some embodiments, the in-vehicle built-in device 130-4 may include an in-vehicle built-in computer, an in-vehicle built-in television, an in-vehicle built-in tablet computer, etc. In some embodiments, user terminal 140 may include a signal transmitter and a signal receiver configured to communicate with a positioning device (not shown) to determine the location of the user and / or user terminal 140. In some embodiments, multimedia platform 110 or storage device 150 may be integrated into user terminal 140. In this case, the functionality available in multimedia platform 110 described above may be similarly implemented by user terminal 140.

[0045] Storage device 150 may store data and / or instructions. In some embodiments, storage device 150 may store data obtained from multimedia platform 110, audio output device 130, and / or user terminal 140. In some embodiments, storage device 150 may store data and / or instructions for multimedia platform 110, audio output device 130, and / or user terminal 140 to perform various functions. In some embodiments, storage device 150 may include mass memory, removable memory, volatile read-write memory, read-only memory (ROM), etc., or any combination thereof. Exemplary mass memory may include magnetic disks, optical disks, solid-state drives, etc. Exemplary removable memory may include flash drives, floppy disks, optical disks, memory cards, compact disks, magnetic tapes, etc. Exemplary volatile read-write memory may include random access memory (RAM). Exemplary RAM may include dynamic random access memory (DRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), static random access memory (SRAM), thyristor random access memory (T-RAM), zero capacitor random access memory (Z-RAM), etc. Exemplary ROM may include masked read only memory (MROM), programmable read only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), compact disc read only memory (CD-ROM), digital versatile disc read only memory (DVROM), etc. In some embodiments, storage device 150 may be implemented on a cloud platform. By way of example only, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-cloud, etc., or any combination thereof. In some embodiments, one or more assemblies in acoustic system 100 may access data or instructions stored in storage device 150 via network 120.In some embodiments, storage device 150 may be directly connected to multimedia platform 110 as a back-end storage device.

[0046] In some embodiments, the multimedia platform 110, the terminal device 140, and / or the storage device 150 may be integrated into the audio output device 130. Specifically, with the advancement of technology and the increasing processing power of the audio output device 130, all processing may be performed by the audio output device 130. For example, the audio output device 130 may be a smart earphone, an MP3 player, a hearing aid, etc., and has a highly integrated electronic assembly, such as a central processing unit (CPU), a graphics processing unit (GPU), etc., and therefore has high processing power.

[0047] 2A and 2B are schematic diagrams of an exemplary acoustic output device according to some embodiments of the present disclosure. Fig. 2A shows a perspective view of acoustic output device 130. Fig. 2B shows an exploded view of acoustic output device 130. Acoustic output device 130 can be described with reference to Figs. 2A and 2B.

[0048] In some embodiments, the audio output device 130 may include an earhook 10, an earphone core housing 20, a circuit housing 30, a backhook 40, an earphone core 50, a control circuit 60, and a battery 70. The earphone core housing 20 and the circuit housing 30 may be located at opposite ends of the earhook 10, and the backhook 40 may be located at an end of the circuit housing 30 that is remote from the earhook 10. The earphone core housing 20 may house different earphone cores 50. The circuit housing 30 may house the control circuit 60 and the battery 70. Both ends of the backhook 40 may be connected to corresponding circuit housings 30. The earhook 10 may refer to a structure configured to hang the audio output device 130 over the user's ear when the user wears the audio output device 130, and to secure the earphone core housing 20 and the earphone core 50 in a predetermined position relative to the user's ear.

[0049] In some embodiments, the ear hook 10 may include an elastic wire. The elastic wire may be configured to allow the ear hook 10 to maintain a shape that conforms to the user's ear and have a certain degree of elasticity. As a result, when a user wears the audio output device 130, a certain degree of elastic deformation can occur according to the shape of the user's ear and head, thereby adapting to users with different ear and head shapes. In some embodiments, the elastic wire may be made of a memory alloy with good deformation recovery ability. Even if the ear hook 10 is deformed by an external force, it can recover to its original shape when the external force is removed, thereby extending the service life of the audio output device 130. In some embodiments, the elastic wire may be made of a non-memory alloy. Lead wires are installed on the elastic wire to establish electrical connections between the earphone core 50 and other components, such as the control circuit 60 and the battery 70, thereby supplying power to the earphone core 50 and transmitting data. In some embodiments, the ear hook 10 may further include a protective sleeve 16 and a housing protection member 17 integrally molded with the protective sleeve 16.

[0050] In some embodiments, the earphone core housing 20 may be configured to house the earphone core 50. The earphone core 50 may include one or more speakers. The one or more speakers may include a bone conduction speaker, an air conduction speaker, etc. The bone conduction speaker may be configured to output sound waves conducted through a solid medium (e.g., the bone structure). For example, the bone conduction speaker may convert an electrical signal into vibrations of the user's skull through direct contact with the user. The air conduction speaker may be configured to output sound waves conducted through the air. For example, the air conduction speaker may convert another electrical signal into air vibrations that are detectable by the user's ear. The number of earphone cores 50 and earphone core housings 20 may be two, corresponding to the user's left and right ears, respectively. More information regarding the earphone core 50 can be found elsewhere herein, for example, in Figures 3-15.

[0051] In some embodiments, the earhook 10 and earphone core housing 20 may be molded separately and then assembled, rather than being directly integrally molded.

[0052] In some embodiments, earphone core housing 20 may provide contact surface 21. Contact surface 21 may contact the user's skin. During operation of acoustic output device 130, bone-conducted sound waves generated by one or more bone-conducted speakers in earphone core 50 may be transmitted to the exterior of earphone core housing 20 (e.g., the user's eardrum) via the contact surface. In some embodiments, the material and thickness of contact surface 21 may affect sound quality by affecting the propagation of bone-conducted sound waves to the user. For example, if the material of contact surface 21 is relatively soft, bone-conducted sound waves in the low frequency range may propagate better than bone-conducted sound waves in the high frequency range. Conversely, if the material of contact surface 21 is relatively hard, bone-conducted sound waves in the high frequency range may propagate better than bone-conducted sound waves in the low frequency range.

[0053] 3A is a schematic diagram of an exemplary audio output device according to some embodiments of the present disclosure. As shown in FIG. 3A, audio output device 300 may include a signal processing module 310 and an output module 320. Signal processing module 310 may receive an electrical signal from a signal source and process the electrical signal. In some embodiments, the electrical signal may be an analog signal or a digital signal. For example, the electrical signal may be a digital signal obtained from multimedia platform 110, terminal device 140, storage device 150, etc.

[0054] The signal processing module 310 may process the electrical signal. For example, the signal processing module 310 may process the electrical signal by performing various signal processing operations (e.g., sampling, digitization, compression, frequency allocation, frequency modulation, encoding, etc., or a combination thereof). The signal processing module 310 may further generate a control signal based on the processed electrical signal.

[0055] The output module 320 may generate and output bone-conducted sound waves (also referred to as bone-conducted sound) and / or air-conducted sound waves (also referred to as air-conducted sound). The output module 320 may receive a control signal from the signal processing module 310 and generate bone-conducted sound waves and / or air-conducted sound waves based on the control signal. As described herein, bone-conducted sound waves refer to sound waves that are conducted via mechanical vibrations through a solid medium (e.g., the skeleton). Air-conducted sound waves refer to sound waves that are conducted via mechanical vibrations through air.

[0056] For convenience of explanation, the output module 320 may include a bone conduction speaker (also called a vibration speaker) 321 and an air conduction speaker 322. The bone conduction speaker 321 and the air conduction speaker 322 may be electrically coupled to the signal processing module 310. The bone conduction speaker 321 may generate bone conduction sound waves within a specific frequency range (e.g., low frequency range, mid-frequency range, high frequency range, mid-low frequency range, mid-high frequency range) based on a control signal generated by the signal processing module 310. The air conduction speaker 322 may generate air conduction sound waves within the same or a different frequency range as the bone conduction speaker 321 based on a control signal generated by the signal processing module 310. In some embodiments, the bone conduction speaker 321 and the air conduction speaker 322 may be two independent functional devices or two independent assemblies of a single device. As used herein, the term "independence of a first device and a second device" refers to the fact that the operation of the first / second device is not due to the operation of the second / first device, or in other words, the operation of the first / second device is not the result of the operation of the second / first device. Taking a bone conduction speaker and an air conduction speaker as examples, the air conduction speaker and the bone conduction speaker are independent because the two speakers are driven independently and generate sound waves by electrical signals.

[0057] Different frequency ranges can be determined according to actual needs. For example, the low frequency range (also called low frequency) may refer to the frequency range of 20Hz to 150Hz, the mid frequency range (also called mid frequency) may refer to the frequency range of 150Hz to 5kHz, the high frequency range (also called high frequency) may refer to the frequency range of 5kHz to 20kHz, the mid-low frequency range (also called mid-low frequency) may refer to the frequency range of 150Hz to 500Hz, and the mid-high frequency range (also called mid-high frequency) may refer to the frequency range of 500Hz to 5kHz. For example, the low frequency range may refer to a frequency range of 20 Hz to 300 Hz, the mid frequency range may refer to a frequency range of 300 Hz to 3 kHz, the high frequency range may refer to a frequency range of 3 kHz to 20 kHz, the mid-low frequency range may refer to a frequency range of 100 Hz to 1000 Hz, and the mid-high frequency range may refer to a frequency range of 1000 Hz to 10 kHz. Note that the frequency range values ​​are for illustrative purposes only and are not limiting. The definitions of the above frequency ranges may vary depending on different application scenarios and different classification standards. For example, in some other application scenarios, the low frequency range may refer to a frequency range of 20 Hz to 80 Hz, the mid frequency range may refer to a frequency range of 160 Hz to 1280 Hz, the high frequency range may refer to a frequency range of 2560 Hz to 20 kHz, the mid-low frequency range may refer to a frequency range of 80 Hz to 160 Hz, and the mid-high frequency range may refer to a frequency range of 1280 Hz to 2560 Hz. Preferably, the different frequency ranges may or may not overlap in frequency.

[0058] 3B is a schematic diagram of another exemplary acoustic output device according to some embodiments herein. In some embodiments, the acoustic output device 305 as shown in FIG. 3B may be similar to or the same as the acoustic output device 300 as shown in FIG. 3A, but the acoustic output device 305 may further include a bone conduction signal processing circuit 316 and an air conduction signal processing circuit 317. The bone conduction signal processing circuit 316 may be configured to process bone conduction signals. The air conduction signal processing circuit 317 may be configured to process air conduction signals. In some embodiments, the electrical signals may include bone conduction signals and air conduction signals. As described herein, bone conduction signals refer to electrical signals associated with bone conduction sound waves and / or electrical signals that affect the generation and output of bone conduction sound waves. Air conduction signals refer to electrical signals associated with air conduction sound waves and / or electrical signals that affect the generation and output of air conduction sound waves. In some embodiments, the bone conduction signal processing circuit 316 may receive bone conduction signals from a signal source, process the bone conduction signals, and generate a corresponding bone conduction control signal. A bone conduction control signal refers to a signal that controls the generation and output of bone-conducted sound waves. Similarly, the air conduction signal processing circuit 317 may receive an air conduction signal from a signal source, process the air conduction signal, and generate a corresponding air conduction control signal. An air conduction control signal refers to a signal that controls the generation and output of air-conducted sound waves.

[0059] The output module 325 may further include a bone conduction speaker 326 and an air conduction speaker 327. The bone conduction speaker 326 and the air conduction speaker 327 may be the same as or similar to the bone conduction speaker 321 and the air conduction speaker 322 of the output module 320 in FIG. 3A , respectively, and therefore will not be described here. The bone conduction speaker 326 may be electrically coupled to the bone conduction signal processing circuit 316. The bone conduction speaker 326 may generate and output bone conduction sound waves within a specific frequency range based on a bone conduction control signal generated by the bone conduction signal processing circuit 316. The air conduction speaker 327 may be electrically coupled to the air conduction signal processing circuit 317. The air conduction speaker 327 may generate and output air conduction sound waves within the same or a different frequency range as the bone conduction speaker 326 based on an air conduction control signal generated by the air conduction signal processing circuit 317.

[0060] In some embodiments, the bone conduction signal processing circuitry 316 and the bone conduction speaker 326 may be integrated or located within the same housing. Similarly, the air conduction signal processing circuitry 317 and the air conduction speaker 327 may be integrated or located within the same housing.

[0061] 3A and 3B, the bone conduction control signal and / or the air conduction control signal may be further processed in signal processing module 310 or 315 to adjust the output characteristics (e.g., frequency, phase, amplitude, etc.) of the bone conduction and / or air conduction sound waves, thereby causing the bone conduction and / or air conduction sound waves to have different output characteristics. For example, the bone conduction control signal and / or the air conduction control signal may include a particular frequency. In some alternative embodiments, the output characteristics (e.g., frequency) of the bone conduction and / or air conduction sound waves may be adjusted by changing or optimizing the structure of each assembly and / or the installation of at least one assembly in at least one of output modules 320 or 325.

[0062] In some embodiments, one or more filters or filter sets may be provided to adjust the output characteristics (e.g., frequency) of the bone-conducted and / or air-conducted sound waves by processing the bone-conducted and / or air-conducted control signals in signal processing modules 310 or 315. Exemplary filters or filter sets may include, but are not limited to, analog filters, digital filters, passive filters, active filters, etc., or combinations thereof.

[0063] In some embodiments, time-domain processing methods may be provided to enrich the acoustics of the audio output from output module 320 or 325. Exemplary time-domain processing methods may include dynamic range control (DRC), time delay, reverberation, etc.

[0064] In some embodiments, the acoustic output device 300 or 305 may further include an active leakage reduction module. In some embodiments, the active leakage reduction module may superimpose and eliminate leaked sound waves (i.e., sound leakage) from the acoustic output device 300 or 305 by directly outputting sound waves without requiring feedback from a reference (e.g., a microphone). The sound waves output by the active leakage reduction module may have the same amplitude, the same frequency, and the opposite phase as the leaked sound waves. In some alternative embodiments, the active leakage reduction module may output sound waves based on reference feedback. For example, a microphone may be placed in the sound field of the acoustic output device 300 or 305 to obtain information about the sound field (e.g., position, frequency, phase, amplitude, etc.) and provide real-time feedback to the active leakage reduction module, thereby dynamically adjusting the output sound waves to reduce or eliminate sound leakage from the acoustic output device 300 or 305. In some embodiments, the active leakage reduction module may be integrated into the output module 320 or 325.

[0065] In some embodiments, the acoustic output device 300 or 305 may further include a beam forming module. The beam forming module may be configured to form a specific acoustic beam of bone-conducted sound waves and / or air-conducted sound waves. In some embodiments, the beam forming module may form a specific acoustic beam by controlling the amplitude and / or phase of the bone-conducted sound waves and / or air-conducted sound waves propagated from the output module 320 (e.g., the bone-conducted speaker 321 and the air-conducted speaker 322) or the output module 325 (e.g., the bone-conducted speaker 326 and the air-conducted speaker 327). The acoustic beam may be, for example, a fan-shaped acoustic beam having a certain angle. By propagating along a specific direction, the acoustic beam can achieve a maximum sound pressure level near a human ear. This also reduces sound leakage from the acoustic output device 300 or 305, since the sound pressure level at other positions in the sound field may be relatively small. In some embodiments, the acoustic output device 300 or 305 may use 3D sound field reconstruction techniques or local sound field control techniques to generate a more ideal three-dimensional sound field so that the user can have a better immersive experience in the sound field. In some embodiments, the beam forming module may be integrated into the output module 320 or 325.

[0066] 4 is a schematic diagram of a resonant system according to some embodiments of the present disclosure. In some embodiments, the effect of the structure and / or installation of one or more assemblies of acoustic output device 130 on the characteristics of the acoustic sound output from acoustic output device 130 may be modeled using a resonant system 400. In some embodiments, resonant system 400 may be described in combination with a mass-spring-damper system. In some embodiments, resonant system 400 may be described in combination with at least two parallel-connected or series-connected mass-spring-damper systems. The motion of resonant system 400 may be described by equation (1):

[0067]

number

[0068] In some embodiments, the resonant frequency of the resonant system 400 can be obtained by solving equation (1). The resonant frequency of the resonant system 400 can be obtained according to equation (2).

[0069]

number

[0070] In some embodiments, the frequency bandwidth may be determined based on the half-power points. The quality factor Q of the resonant system 400 may be determined according to equation (3).

[0071]

number

[0072] In some embodiments, the bone conduction speaker 321, the air conduction speaker 322, the bone conduction speaker 326, or the air conduction speaker 327 may be a single resonant system or a combination of at least two resonant systems. In some embodiments, the output module 320 or 325 may further include at least two bone conduction speakers and / or at least two air conduction speakers.

[0073] For bone-conducted sound waves, the frequency and bandwidth of the bone-conducted sound waves may be adjusted by changing the parameters exemplified above (e.g., mass, damping, etc.). For example, the resonant frequency may be adjusted by increasing the mass, thereby decreasing the elastic coefficient (e.g., by using a spring with a low elastic coefficient, using a material with a low Young's modulus for the vibration transmission structure, or reducing the thickness of the vibration transmission structure). In this case, the resonant system 400 (e.g., a bone conduction speaker) can output vibrations in the mid-low frequency range. For example, the resonant frequency may be adjusted to the mid-high frequency range by decreasing the mass of the resonant system 400 or increasing the elastic coefficient of the resonant system 400 (e.g., by using a spring with a high elastic coefficient, using a material with a high Young's modulus for the vibration transmission structure, increasing the thickness of the vibration transmission structure, or providing reinforcing ribs or other reinforcing structures on the vibration transmission structure). In this case, the resonant system 400 can output vibrations in the mid-high frequency range. For example, the bandwidth of the vibration output by the resonant system 400 may be adjusted by changing the quality factor Q. Furthermore, for example, a composite resonant system including at least two resonant systems may be provided. The resonant frequency and quality factor Q of each resonant system may be adjusted individually. The center frequency and bandwidth of a composite resonant system may be adjusted by connecting at least two resonant systems in series or in parallel.

[0074] For air-conducted acoustic waves, the frequency and bandwidth of the air-conducted acoustic waves may similarly be adjusted by changing the above-described exemplary parameters (e.g., mass, attenuation, etc.). In some embodiments, one or more acoustic structures may be provided to adjust the frequency of the air-conducted acoustic waves. The one or more acoustic structures may include, for example, an acoustic cavity, an acoustic tube, an acoustic hole, a decompression hole, an acoustic mesh, an acoustic cotton, a passive diaphragm, etc., or a combination thereof. For example, the elastic coefficient of the system 400 may be adjusted by changing the volume of the acoustic cavity. Increasing the volume of the acoustic cavity may decrease the elastic coefficient of the system. In some embodiments, the mass and attenuation of the system 400 may be adjusted by installing an acoustic tube or an acoustic hole. The longer the acoustic tube or acoustic hole, the smaller the cross-sectional area, the greater the mass, and the less attenuation. Conversely, the shorter the acoustic tube or acoustic hole, the larger the cross-sectional area, the smaller the mass, and the greater the attenuation. In some embodiments, the attenuation of the system 400 may be adjusted by placing an acoustically resistive material (e.g., acoustic holes, acoustic mesh, acoustic cotton, etc.) in the path along which the air-conducted sound waves propagate. In some embodiments, a passive vibrating membrane may be installed to enhance the air-conducted sound waves in the low frequency range. In some embodiments, the phase, amplitude, and / or frequency range of the air-conducted sound waves may be adjusted by installing one or more acoustic tubes and / or anti-phase holes. In other embodiments, a series of air-conducted speakers may be provided. A sound field with a specific spatial distribution may be formed by adjusting the amplitude, frequency range, and phase of each air-conducted speaker.

[0075] In some embodiments, a user may adjust the output characteristics of bone-conducted and / or air-conducted sound waves (e.g., by setting the amplitude, frequency, and / or phase of the control signal). In some embodiments, parameters of the resonant system 400 and user-set control signals may adjust the output characteristics of bone-conducted and / or air-conducted sound waves.

[0076] FIG. 5A is a schematic diagram of an exemplary bone conduction speaker according to some embodiments herein. The bone conduction speaker 500 may include a vibration assembly 510. The vibration assembly 510 may include or be housed in a housing 520. The vibration assembly 510 may be electrically connected to the signal processing module 310 or 315 to receive a bone conduction control signal and generate bone conduction sound waves based on the bone conduction control signal. For example, the vibration assembly 510 may be or include any element (e.g., a vibration motor, an electromagnetic vibration device, etc.) that converts an electrical signal (e.g., a bone conduction control signal) into a mechanical vibration signal. Exemplary signal conversion methods include, but are not limited to, electromagnetic (e.g., moving coil, balanced armature, magnetostrictive), piezoelectric, electrostatic, etc. The internal structure of the vibration assembly 510 may be a single-resonance system or a multiple-resonance system. In some embodiments, the vibration assembly 510 can generate mechanical vibrations based on the bone conduction control signal. The mechanical vibrations can generate bone conduction sound waves.

[0077] As shown in FIG. 5A , the vibration assembly 510 may include a magnetic circuit system 511, a diaphragm 512, and one or more coils 513. The magnetic circuit system 511 may be configured to generate a magnetic field. In some embodiments, the magnetic circuit system 511 may include a magnetic gap. The magnetic circuit system 511 may generate a magnetic field in the magnetic gap. The diaphragm 512 may contact a user's skin (e.g., the skin on the user's head) and transmit bone-conducted sound waves to the user's cochlea when the user wears the acoustic output device 300 or 305. The diaphragm 512 may be referred to as the bottom wall of the housing 520. As used herein, the "bottom" or "top" portion of the assembly is described relative to the user's skin. For example, in the housing 520, the wall closest to the user's skin (e.g., the wall that contacts the skin) is referred to as the top wall or front wall, and the wall farthest from the user's skin (e.g., the wall opposite the top wall) is referred to as the bottom wall or back wall. The one or more coils 513 may be mechanically connected to the diaphragm 512. In some embodiments, the one or more coils 513 may be electrically connected to the signal processing module 310 or 315. In some embodiments, the one or more coils 513 may be disposed within a magnetic gap. When a current is applied to the one or more coils 513, the one or more coils 513 vibrate in the magnetic field and can drive the diaphragm 512 to vibrate, generating bone-conducted sound waves.

[0078] FIG. 5B is a schematic diagram of an exemplary air conduction speaker according to some embodiments of the present disclosure. In some embodiments, the air conduction speaker 550 may be a general speaker that generates sound waves that propagate through air. In some embodiments, the air conduction speaker 550 may be a dedicated speaker customized to meet certain requirements (e.g., requirements regarding output characteristics). In some embodiments, the air conduction speaker 550 may include a diaphragm 551 and a driver 552. The diaphragm 551 may be a thin film made of a material that is sensitive to a variable magnetic field. Exemplary materials for the diaphragm 551 may include polyarylate (PAR), thermoplastic elastomer (TPE), polytetrafluoroethylene (PTFE), etc. The driver 552 may be a balanced armature driver, a moving coil driver, etc., or a combination thereof. In some embodiments, the driver 552 may receive an air conduction control signal from the signal processing module 310 or 315 (e.g., the air conduction signal processing circuit 317) and drive the diaphragm 551 to vibrate based on the air conduction control signal to generate air conduction sound waves.

[0079] In some embodiments, an air conduction speaker 550 including a diaphragm 551 and a driver 552 may be housed within a housing 560. In some embodiments, the diaphragm 551 may be large such that the cavity of the housing 560 is divided by the diaphragm 551 into two portions including a front portion 561 and a rear portion 562. The front portion 561 refers to the front portion of the diaphragm 551 (e.g., the bottom portion shown in FIG. 5B ) and may be referred to as the "front cavity." The rear portion 562 refers to the rear portion of the diaphragm 551 (e.g., the top portion shown in FIG. 5B ) and may be referred to as the "rear cavity."

[0080] In some embodiments, at least one acoustic hole (e.g., acoustic hole 570) may be located in a wall of the front cavity of housing 560. The acoustic hole may be a through-hole. Air-conducted sound waves generated in the front cavity of housing 560 can propagate to the outside of housing 560 through the at least one acoustic hole. In some embodiments, when a user wears acoustic output device 300 or 305, the acoustic hole may be directed toward the user's ear canal.

[0081] In some embodiments, an acoustic tube (not shown) may be coupled to the acoustic hole. In some embodiments, air-conducted sound waves that pass through the acoustic hole may enter the acoustic tube and propagate along a particular direction through the acoustic tube. This allows the acoustic tube to change the propagation direction of the air-conducted sound waves.

[0082] In some embodiments, decompression holes (not shown) may be installed in the wall of the rear cavity of the housing 560. The decompression holes may be through-holes that help balance the pressure between the rear cavity of the housing 560 and the outside. The decompression holes may also help adjust the frequency response of the air conduction speaker 550 at low frequencies.

[0083] In some embodiments, air-conducted sound waves propagate to the outside through the decompression holes, potentially resulting in sound leakage. In some embodiments, specially designed decompression holes can reduce or suppress sound leakage. For example, the decompression holes may be larger in size so that the resonance peak (Helmholtz resonance) of the rear cavity of the housing 560 can accommodate higher frequencies. In this way, sound leakage of mid- to low-frequency sounds propagating through the decompression holes can be suppressed. Additionally, larger decompression hole sizes provide smaller acoustic resistance, potentially reducing the sound pressure of sound waves at the decompression holes, thereby reducing sound leakage.

[0084] In some further embodiments, an acoustic mesh (not shown) can be installed in the decompression holes to reduce the intensity of the resonance peaks, thereby lowering the frequency response of the rear cavity of the housing 520 and reducing sound leakage.

[0085] In some embodiments, the output characteristics of bone-conducted sound waves may be adjusted by changing the stiffness of the diaphragm 512 and / or the housing 520 (e.g., the size, elastic modulus of the material, ribs, and / or other mechanical structures of the diaphragm 512 and / or the housing 520). In some embodiments, the output characteristics of air-conducted sound waves may be adjusted by changing the shape, elastic modulus, and damping of the diaphragm 551. In some embodiments, the output characteristics of air-conducted sound waves may be adjusted by changing the number, position, size, and / or shape of at least one acoustic hole and / or decompression hole. For example, the acoustic hole 570 may be provided with a damping structure (e.g., an acoustic mesh) to adjust the acoustic effect of the air-conducted speaker 550.

[0086] The number, size, shape (e.g., cross-sectional shape), and / or position of the one or more additional acoustic structures (e.g., acoustic holes, acoustic tubes, decompression holes, and / or acoustic mesh) exemplified above may be set according to actual needs and are not limited herein. In some embodiments, the number, size, shape, and / or position of the one or more additional acoustic structures may be optimized according to sound leakage from the audio output device. In some embodiments, optimization may be performed based on the leakage frequency response curve described below. Furthermore, the spatial arrangement of the bone conduction speaker 500 and the air conduction speaker 550, and / or one or more components of the bone conduction speaker 500 and the air conduction speaker 550, is not limited herein. For example, the spatial arrangement of the bone conduction speaker 500 and the air conduction speaker 550 may vary according to actual needs and is not limited herein (e.g., the air conduction speaker 550 may be installed in parallel with the bone conduction speaker 500, or the air conduction speaker 550 and the bone conduction speaker 500 may be installed stacked). Also, for example, the position of the driving device 552 and / or the diaphragm 551 in the housing 560, the direction of the diaphragm 551 (for example, the forward direction), etc. may be changed according to actual needs and are not limited.

[0087] The acoustic output device according to the present disclosure may be combined with a bone conduction speaker (e.g., bone conduction speaker 500) and an air conduction speaker (e.g., air conduction speaker 550) to provide a user with enhanced acoustic effects and tactile sensations. In some embodiments, the bone conduction sound waves and air conduction sound waves output by the acoustic output device may include sound waves of different frequencies.

[0088] FIG. 6 is a schematic diagram of an exemplary acoustic output device according to some embodiments of the present disclosure. As shown in FIG. 6, the acoustic output device 600 includes a first housing 610, a second housing 620, a bone conduction speaker 630, and an air conduction speaker 640. The bone conduction speaker 630 may be the same as or similar to the bone conduction speaker 500 of FIG. 5. The structure of the bone conduction speaker 630 may be simplified as shown in FIG. 6. The bone conduction speaker 630 may be electrically coupled to the bone conduction signal processing circuit 316 and configured to generate bone conduction sound waves based on a bone conduction control signal generated by the bone conduction signal processing circuit 316. The bone conduction speaker 630 may be located inside the bottom wall of the first housing 610. The bone conduction sound waves generated by the bone conduction speaker 630 may be transmitted to a user through the bottom wall of the first housing 610. The bottom wall may be in contact with the user's skin (e.g., as indicated by the dashed line 650). In some embodiments, the diaphragm of the bone conduction speaker 630 may be mechanically connected to the bottom wall of the first housing 610, or the bottom wall of the first housing 610 may be part of the bone conduction speaker 630 and may be considered the diaphragm of the bone conduction speaker 630. In this case, the diaphragm may vibrate along a direction perpendicular or substantially perpendicular to the user's skin (dashed line 650). In some alternative embodiments, the bone conduction speaker 630 may be located on the top wall of the first housing 610, opposite the bottom wall of the first housing 610. As used herein, if the difference between the angles of two directions and 0 degrees (or 180 degrees) is less than (e.g., 2 degrees, 5 degrees, 10 degrees), the two directions may be considered to be substantially parallel to each other. Similarly, if the difference between the angles of two directions and 90 degrees is less than an angle threshold (e.g., 2 degrees, 5 degrees, 10 degrees), the two directions may be considered to be substantially perpendicular to each other.

[0089] The air conduction speaker 640 may be coupled to the air conduction signal processing circuit 317 and may be configured to generate air conduction sound waves based on an air conduction control signal generated by the air conduction signal processing circuit 317. The air conduction speaker 640 may be located next to the bone conduction speaker 630. Specifically, the bone conduction speaker 630 and the air conduction speaker 640 may be located along a reference plane (e.g., a plane on which the user's skin or the bottom wall of the first housing 610 is located). The air conduction speaker 640 may be located on one side of the bone conduction speaker 630.

[0090] The bone conduction speaker 630 may be located within the cavity 611 of the first housing 610. The air conduction speaker 640 may be located within the cavity 621 of the second housing 620. The cavity 611 of the first housing 610 and the cavity 621 of the second housing 620 may not be connected to each other. The second housing 620 may be installed next to the first housing 610. In some embodiments, the first housing 610 and the second housing 620 may be fixedly connected and attached to each other. For example, the first housing 610 and the second housing 620 may share the same sidewall therebetween. In some embodiments, the first housing 610 and the second housing 620 may be separate (e.g., there is a distance between the first housing 610 and the second housing 620) and connected to each other by a connection assembly.

[0091] The front side of the diaphragm of the air conduction speaker 640 may face in any direction. In some embodiments, the front side of the diaphragm of the air conduction speaker 640 may face downward toward the bottom wall of the second housing 620 (i.e., toward the dashed line 650 in FIG. 6 ). The vibration direction of the bone conduction speaker 630 (i.e., the direction of bone conduction sound waves propagating from the bone conduction speaker 630) may be perpendicular or substantially perpendicular to the user's skin, and the central vibration direction of the diaphragm of the air conduction speaker 640 may be perpendicular or substantially perpendicular to the user's skin. As used herein, the central vibration direction of the diaphragm refers to the vibration direction of the center of the diaphragm of the air conduction speaker 640. The vibration direction of the bone conduction speaker 630 may be the same as the vibration direction of the diaphragm of the bone conduction speaker 630. In this case, the central vibration direction of the diaphragm of the air conduction speaker 640 may be parallel to the vibration direction of the bone conduction speaker 630.

[0092] In some embodiments, at least one acoustic hole may be provided in a wall of the second housing 620. The at least one acoustic hole may allow air-conducted sound waves to propagate from the cavity 621. For example, the first acoustic hole 622 may be provided in a top wall of the second housing 620. The second acoustic hole 623 may be provided in a side wall of the second housing 620. In some embodiments, the second acoustic hole 623 may be located below the front surface of the air-conducted speaker 640 (e.g., the diaphragm of the air-conducted speaker 640) in a vertical direction perpendicular to the bottom wall of the second housing 620.

[0093] When a user wears the acoustic output device 600, the first housing 610 may be directly or indirectly connected to the user's skin. The bottom wall of the first housing 610, which is in contact with the user's skin, can transmit bone-conducted sound waves to the user's cochlea through the user's skin and bones. In some embodiments, the air-conducted speaker 640 may be closer to the listening position (e.g., the user's ear) than the bone-conducted speaker 630. The second acoustic hole 623 of the second housing 620 may be positioned toward the listening position so that air-conducted sound waves can propagate directly to the user's ear, reducing sound loss and increasing the volume of sound heard by the user.

[0094] It should be noted that at least one acoustic hole (e.g., acoustic holes 622 and 623) may be provided for purposes of illustration and not limitation. In some alternative embodiments, acoustic hole 623 may be omitted. The front cavity of second housing 620 may be omitted. Air-conducted sound waves generated by the diaphragm of air-conducted speaker 640 may propagate directly to the outside of second housing 620. In this case, the diaphragm of the air-conducted speaker may form a wall (e.g., a bottom wall) of second housing 620. In some embodiments, one or more additional acoustic structures (e.g., acoustic mesh, decompression holes, acoustic tubes, etc.) may be provided.

[0095] The bone conduction speaker 630 may be electrically coupled to the bone conduction signal processing circuit 316. The bone conduction speaker 630 may generate and output bone conduction sound waves within a specific frequency range (e.g., low frequency range, mid-frequency range, high frequency range, mid-low frequency range, mid-high frequency range, etc.) based on a bone conduction control signal generated by the bone conduction signal processing circuit 316. The air conduction speaker 640 may be electrically coupled to the air conduction signal processing circuit 317. The air conduction speaker 640 may generate and output air conduction sound waves within the same or a different frequency range as the bone conduction speaker 630 based on an air conduction control signal generated by the air conduction signal processing circuit 317.

[0096] For example, bone-conducted sound waves may include mid-high frequencies, and air-conducted sound waves may include mid-low frequencies. The mid-low frequency air-conducted sound waves can be supplemented with the mid-high frequency bone-conducted sound waves. The total output of the acoustic output device may cover mid-low and mid-high frequencies. In this case, better sound quality (especially at low frequencies) can be provided, and strong vibrations at low frequencies of bone-conducted speakers can be avoided.

[0097] For example, bone-conducted sound waves may include low- to mid-frequency sounds, and air-conducted sound waves may include high- to mid-frequency sounds. In this case, since the user is sensitive to low- to mid-frequency bone-conducted sound waves and / or high- to mid-frequency air-conducted sound waves, the audio output device can provide a notification or warning to the user via a bone-conducted speaker and / or an air-conducted speaker.

[0098] Further, for example, air-conducted sound waves may include low-mid frequencies, and bone-conducted sound waves may include frequencies in a wider frequency range (wider frequency range) than air-conducted sound waves. The output of low-mid frequencies may be increased, and sound quality may be improved. More details regarding the frequency distribution of bone-conducted and / or air-conducted sound waves may be found elsewhere herein, for example, in Figures 17-21.

[0099] It should be noted that the above description is for illustrative purposes only and is not intended to limit the scope of the present specification. Those skilled in the art may make various changes and modifications based on the description herein. However, these changes and modifications do not depart from the scope of the present specification. For example, the relative positions of the bone conduction speaker 630 and the air conduction speaker 640, the mass, shape, and / or size of the first housing 610 and / or the second housing 620, one or more additional acoustic structures, etc., can be modified and optimized according to various needs and are not limited herein.

[0100] 7 is a schematic diagram of an exemplary acoustic output device according to some embodiments herein. In some embodiments, the acoustic output device 700 may be the same as or similar to the acoustic output device 600, except that the front side of the diaphragm of the air conduction speaker 740 may face upward relative to the bottom of the second housing 720 (i.e., toward the top wall of the second housing 720). When a user wears the acoustic output device 700, the bottom wall of the first housing 710, which houses the bone conduction speaker 730, may come into contact with the user's skin (e.g., as indicated by the horizontal dashed line 750).

[0101] In some embodiments, the acoustic hole 723 may be located on a side wall of the second housing 720. The acoustic hole 723 may be located above the front surface of the air conduction speaker 740 (e.g., the surface of the diaphragm of the air conduction speaker 740) in a direction perpendicular to the bottom wall of the second housing 720. Also, a decompression hole (not shown in FIG. 7 ) may be located on a side wall of the second housing 720. The decompression hole may be located below the front surface of the air conduction speaker 740 in a direction perpendicular to the bottom wall of the second housing 720.

[0102] FIG. 8 is a schematic diagram of an exemplary acoustic output device according to some embodiments of the present disclosure. As shown in FIG. 8 , the acoustic output device 800 may include a housing 810, a bone conduction speaker 830, and an air conduction speaker 840. In some embodiments, the acoustic output device 800 may be similar to the acoustic output device 700, except that the bone conduction speaker 830 and the air conduction speaker 840 may share the same cavity in the housing 810. The bone conduction speaker 830 may be located inside the bottom wall of the housing 810. Bone conduction sound waves generated by the bone conduction speaker 830 may be transmitted to the user through the bottom wall of the housing 810. The bottom wall of the housing 810 may be in contact with the user's skin (e.g., as indicated by dashed line 850). The air conduction speaker 840 may be located next to the bone conduction speaker 830 within the housing 810.

[0103] In some embodiments, the housing 810 may define a front cavity together with the front surface of the air conduction speaker 840 (e.g., the surface of the diaphragm of the air conduction speaker 840). The front surface of the air conduction speaker 840 may face upward relative to the bottom wall of the housing 810 and radiate air conduction sound waves into the front cavity. In some embodiments, the air conduction speaker 840 may be fixed between a side wall of the housing 810 and a fixed side that protrudes into the cavity of the housing 810. For example, the fixed side may extend in a vertical direction perpendicular to the bottom wall of the housing 810. The combination of the fixed side, the side wall of the housing 810, and the diaphragm of the air conduction speaker 840 may form the front cavity of the air conduction speaker 840.

[0104] In some embodiments, the housing 810 may provide at least one acoustic hole. For example, the acoustic hole 822 may be located on a side wall of the front cavity of the housing 810. In some embodiments, the acoustic hole 822 may face a listening position (e.g., a user's ear when the user wears the audio output device 800). The acoustic hole 822 may be located above the front surface of the air conduction speaker (e.g., the surface of the diaphragm of the air conduction speaker 840) in a vertical direction perpendicular to the bottom wall of the housing 810. In some alternative embodiments, the front surface of the air conduction speaker 840 (e.g., the surface of the diaphragm of the air conduction speaker 840) may face downward relative to the bottom of the housing 810. In this case, the position of the acoustic hole 822 may be changed accordingly. In some embodiments, the housing 810 may further provide a decompression hole 812 that equalizes pressure within a rear cavity of the air conduction speaker 840 defined by the housing 810. 8, the bone conduction speaker 830 may be located in the rear cavity of the air conduction speaker 840. The decompression hole 812 and the air conduction speaker 840 may be located on opposite sides of the bone conduction speaker 830. The distance between the acoustic hole 822 and the air conduction speaker 840 may be shorter than the distance between the decompression hole 812 and the air conduction speaker 840.

[0105] 9 and 10 are schematic diagrams of leakage frequency response curves of an acoustic output device 600 according to some embodiments of the present disclosure. The leakage frequency response curve of the acoustic output device 600 refers to a curve in which sound leakage from the acoustic output device 600 changes with sound frequency. For the acoustic output device 600, the air conduction speaker 640 may be installed next to the bone conduction speaker 630. Leakage frequency response curves for various conditions of the acoustic output device 600 can be provided. The horizontal axis may represent sound frequency. The vertical axis may represent the amount of sound leakage from the acoustic output device 600. As shown in FIG. 9 , a first leakage frequency response curve 910 is provided when the acoustic output device 600 includes only the bone conduction speaker 630 (omitting the air conduction speaker 640). A second leakage frequency response curve 920 is provided when at least one acoustic hole is installed in the wall of the front cavity of the second housing 620. A third leakage frequency response curve 930 is provided under the condition that at least one acoustic hole on the wall of the front cavity of the second housing 620 is omitted. As shown in Figure 10, a fourth leakage frequency response curve 1010 is provided under the condition that at least one acoustic hole is installed on the wall of the rear cavity of the second housing 620. A fifth leakage frequency response curve 1020 is provided under the condition that at least one acoustic hole on the wall of the rear cavity of the second housing 620 is omitted. A sixth leakage frequency response curve 1030 is provided under the condition that the mass of the second housing 620 is increased.

[0106] As can be estimated, when the audio output device 600 includes only the bone conduction speaker 630 (omitting the air conduction speaker 640), sound leakage at most frequencies is greater than sound leakage when the audio output device 600 simultaneously includes both the bone conduction speaker 630 and the air conduction speaker 640. Therefore, when the air conduction speaker 640 is installed next to the bone conduction speaker 630, the combination of the bone conduction speaker 630 and the air conduction speaker 640 can reduce sound leakage. Furthermore, providing at least one acoustic hole in the wall of the front or rear cavity of the housing 620 has little effect on the sound leakage of the audio output device 600. It can also be estimated that the vibration amplitude of the non-vibrating walls of the first housing 610 and the second housing 620 (e.g., the top wall and side wall of the first housing 610) can be reduced by increasing the mass of the audio output device 600 and the rigidity of the walls of the first housing 610 and / or the second housing 620. Therefore, sound leakage from the acoustic output device 600 can be effectively reduced within a specific frequency range (for example, a frequency range greater than 400 Hz).

[0107] FIG. 11 is a schematic diagram of an exemplary acoustic output device according to some embodiments of the present disclosure. As shown in FIG. 11 , the acoustic output device 1100 may include a housing 1110, a bone conduction speaker 1120, and an air conduction speaker 1130. The bone conduction speaker 1120 may be located inside the bottom wall of the housing 1110. Bone conduction sound waves generated by the bone conduction speaker 1120 may be transmitted to a user through the bottom wall of the housing 1110. The bottom wall may be in contact with the user's skin (e.g., as indicated by dashed line 1150). In some embodiments, the diaphragm of the bone conduction speaker 1120 may be mechanically connected to the bottom wall of the housing 1110, or the bottom wall of the housing 1110 may be part of the bone conduction speaker 1120 and may be considered as the diaphragm of the bone conduction speaker 1120. In this case, the diaphragm may vibrate in a direction perpendicular or substantially perpendicular to the user's skin (dashed line 1150). In some alternative embodiments, the bone conduction speaker 1120 may be located on the top wall of the housing 1110, facing the bottom wall of the housing 1110. The air conduction speaker 1130 and the bone conduction speaker 1120 may be stacked. Specifically, the air conduction speaker 1130 may be located above the bone conduction speaker with respect to a reference plane (e.g., a plane on which the user's skin or the bottom wall of the housing 1110 is located). The housing 1110 may include a first cavity 1111 and a second cavity 1112, and the first cavity 1111 and the second cavity 1112 are arranged along a direction from the top wall to the bottom wall of the housing 1110. In some embodiments, the first cavity 1111 and the second cavity 1112 may not be connected to each other. For example, the first cavity 1111 and the second cavity 1112 may be separated by a film, an inner wall of the housing 1110, or the like. The bone conduction speaker 1120 may be located in a first cavity 1111 of the housing 1110. The air conduction speaker 1130 may be located in a second cavity 1112 of the housing 1110. As shown in FIG. 11 , the second cavity 1112 may be the front cavity of the air conduction speaker 1130.Alternatively, when the air conduction speaker 1130 is inverted (ie, turned upside down), the second cavity 1112 may be the rear cavity of the air conduction speaker 1130.

[0108] In some embodiments, the front side of the air conduction speaker 1130 may face the bottom of the housing 1110. The vibration direction of the bone conduction speaker 1120 (i.e., the direction of bone conduction sound waves propagating from the bone conduction speaker 1120) may be perpendicular to the user's skin, and the central vibration direction of the diaphragm of the air conduction speaker 1130 may be perpendicular to the user's skin. In this case, the central vibration direction of the diaphragm of the air conduction speaker 1130 may be the same as the vibration direction of the bone conduction speaker 1120.

[0109] In some embodiments, a decompression hole 1113 may be provided on a side wall of the housing 1110 to reduce sound leakage from the acoustic output device 1100. The decompression hole 1113 may connect the rear cavity of the air conduction speaker 1130 to the outside and is also referred to as a rear cavity acoustic hole. In some embodiments, the acoustic hole 1114 may be located on a side wall of the front cavity 1112 of the air conduction speaker 1130. The acoustic hole 1114 may connect the front cavity 1112 to the outside. In some embodiments, the acoustic hole 1114 may be located on the front surface of the air conduction speaker 1130 (e.g., on the surface of the diaphragm of the air conduction speaker 1130). The acoustic hole 1114 can transmit air-conducted sound waves to a listening position (e.g., a user's ear when the user wears the acoustic output device 1100).

[0110] In some embodiments, the air conduction speaker 1130 may be closer to the listening position than the bone conduction speaker 1120, and the acoustic hole 1114 may be toward the listening position, so that air conduction sound waves can propagate directly to the listening position via the acoustic hole 1114. In some alternative embodiments, the acoustic hole 1114 may be omitted. The front cavity of the housing 1110 (e.g., the side wall toward the listening position) may be omitted. Air conduction sound waves generated by the diaphragm of the air conduction speaker 1130 can propagate directly to the outside of the housing 1110. In this case, the diaphragm of the air conduction speaker may form a wall of the housing 1110.

[0111] The bone conduction speaker 1120 may be electrically coupled to the bone conduction signal processing circuit 316. The bone conduction speaker 1120 may generate and output bone conduction sound waves within a specific frequency range (e.g., low frequency range, mid frequency range, high frequency range, mid-low frequency range, mid-high frequency range, etc.) based on a bone conduction control signal generated by the bone conduction signal processing circuit 316. The air conduction speaker 1130 may be electrically coupled to the air conduction signal processing circuit 317. The air conduction speaker 1130 may generate and output air conduction sound waves within the same or a different frequency range as the bone conduction speaker 1120 based on an air conduction control signal generated by the air conduction signal processing circuit 317.

[0112] For example, bone-conducted sound waves may include mid-high frequencies, and air-conducted sound waves may include mid-low frequencies. The mid-low frequency air-conducted sound waves can be supplemented with the mid-high frequency bone-conducted sound waves. The total output of the acoustic output device may cover mid-low and mid-high frequencies. In this case, better sound quality (especially at low frequencies) can be provided, and strong vibrations at low frequencies of bone-conducted speakers can be avoided.

[0113] More detailed information regarding the frequency distribution of bone-conducted and / or air-conducted sound waves can be found elsewhere herein, for example, in Figures 17-21.

[0114] It should be noted that the above description is for illustrative purposes only and is not intended to limit the scope of the present specification. Those skilled in the art may make various changes and modifications based on the description herein. However, these changes and modifications do not depart from the scope of the present specification. For example, the relative positions of the bone conduction speaker 1120 and the air conduction speaker 1130, the mass, shape, and / or size of the housing 1110, one or more additional acoustic structures, etc., can be modified and optimized according to various needs and are not limited herein. For example, the bone conduction speaker 1120 and the air conduction speaker 1130 may be housed in two housings, respectively.

[0115] FIG. 12 is a schematic diagram of an exemplary acoustic output device according to some embodiments of the present disclosure. As shown in FIG. 12 , the acoustic output device 1200 may include a housing 1210, a bone conduction speaker 1220, and an air conduction speaker 1230. In some embodiments, the acoustic output device 1200 may be the same as or similar to the acoustic output device 1100, except that the front side of the diaphragm of the air conduction speaker 1230 may face upward relative to the bottom wall of the housing 1210 (i.e., toward the top wall of the housing 1210). The bone conduction speaker 1220 may be located inside the bottom wall of the housing 1210. Bone conduction sound waves generated by the bone conduction speaker 1220 may be transmitted to the user through the bottom wall of the housing 1210. The bottom wall may be in contact with the user's skin (e.g., as indicated by dashed line 1250). The air conduction speaker 1230 and the bone conduction speaker 1220 may be stacked. In some embodiments, the air conduction speaker 1230 and the bone conduction speaker 1220 may be installed in sequence along the housing 1210 from the top wall to the bottom wall. The air conduction speaker 1230 and the bone conduction speaker 1220 may share the same cavity in the housing 1210. In some embodiments, the front surface of the air conduction speaker 1230 may face upward relative to the bottom wall of the housing 1210.

[0116] In some embodiments, the acoustic hole 1214 may be located in a side wall of the housing 1210. For example, the acoustic hole 1214 may be located in a side wall of the front cavity of the air conduction speaker 1230. In some embodiments, the decompression hole 1213 may be located in a side wall of the housing 1210. For example, the decompression hole 1213 may be located in a side wall of the rear cavity of the air conduction speaker 1230. The bone conduction speaker 1220 may be located in the rear cavity of the air conduction speaker 1230.

[0117] 13 and 14 are schematic diagrams of leakage frequency response curves of an acoustic output device 1100 according to some embodiments of the present disclosure. The air conduction speaker 1130 and the bone conduction speaker 1120 of the acoustic output device 1100 may be stacked. Leakage frequency response curves for various conditions of the acoustic output device 1100 can be provided. The horizontal axis may represent sound frequency. The vertical axis may represent the amount of sound leakage from the acoustic output device 1100. As shown in FIG. 13 , a first leakage frequency response curve 1310 is provided when the acoustic output device 1100 includes only the bone conduction speaker 1120 (omitting the air conduction speaker 1130). A second leakage frequency response curve 1320 is provided when at least one acoustic hole is present in the wall of the rear cavity of the housing 1110. A third leakage frequency response curve 1330 is provided when at least one acoustic hole on the wall of the rear cavity of the housing 1110 is omitted. 14, a fourth leakage frequency response curve 1410 is provided under the condition that at least one acoustic hole is present in the wall of the front cavity of the housing 1110. A fifth leakage frequency response curve 1420 is provided under the condition that at least one acoustic hole on the wall of the front cavity of the housing 1110 is omitted. A sixth leakage frequency response curve 1430 is provided under the condition that the mass of a portion of the housing 1110 is increased.

[0118] As can be estimated, when the audio output device 1100 includes only the bone conduction speaker 1120 (omitting the air conduction speaker 1130), sound leakage within a certain frequency range (e.g., 1000 Hz to 3000 Hz, 8000 Hz to 10 kHz) is greater than sound leakage when the audio output device 1100 simultaneously includes both the bone conduction speaker 1120 and the air conduction speaker 1130. Furthermore, providing at least one acoustic hole in the wall of the rear cavity of the housing 1110 can reduce sound leakage within a certain frequency range (e.g., less than 1000 Hz) of the audio output device 1100. However, providing at least one acoustic hole in the wall of the front cavity of the housing 1110 can increase sound leakage within a certain frequency range (e.g., 3000 Hz to 10 kHz) of the audio output device 1100. As can be further deduced, the vibration amplitude of a non-vibrating wall of the housing 1110 can be reduced by increasing the mass of the acoustic output device 1100 and the stiffness of at least one wall of the housing 1110. Therefore, sound leakage within a specific frequency range of the acoustic output device 1100 (e.g., a frequency range of 6000 Hz to 10000 Hz) can be effectively reduced.

[0119] FIG. 15 is a schematic diagram of an exemplary acoustic output device according to some embodiments of the present disclosure. As shown in FIG. 15 , the acoustic output device 1500 may include a bone conduction speaker 1520 and an air conduction speaker 1530. The bone conduction speaker 1520 and the air conduction speaker 1530 may be housed in the same housing 1510. The bone conduction speaker 1520 may be located inside a bottom wall 1511 of the housing 1510. When a user wears the acoustic output device 1500, bone conduction sound waves generated by the bone conduction speaker 1520 can be transmitted to the user through the bottom wall 1511 of the housing 1510. The bottom wall 1511 may be in contact with the user's skin (e.g., as indicated by dashed line 1550). In some embodiments, the diaphragm of the bone conduction speaker 1520 may be mechanically connected to the bottom wall of the housing 1510, or the bottom wall of the housing 1510 may be part of the bone conduction speaker 1520 and may be considered as the diaphragm of the bone conduction speaker 1520. In this case, the diaphragm can vibrate in a direction perpendicular or substantially perpendicular to the user's skin (dashed line 1550). In some alternative embodiments, the bone conduction speaker 1520 may be located on the top wall of the housing 1510, opposite the bottom wall of the housing 1510.

[0120] The air conduction speaker 1530 may be installed perpendicular to the bone conduction speaker 1520. That is, the vibration direction of the diaphragm of the bone conduction speaker 1520 may be perpendicular to the central vibration direction of the diaphragm of the air conduction speaker 1530. As shown in FIG. 15 , the diaphragm 1512 of the air conduction speaker 1530 may form a side wall of the housing 1510, so that there is no front cavity in the air conduction speaker 1530. The front side of the diaphragm of the air conduction speaker 1530 may face the listening position. Air-conducted sound waves generated by the air conduction speaker 1530 can propagate directly in the listening direction. In some alternative embodiments, the side wall of the housing 1510 may be provided in front of the diaphragm of the air conduction speaker 1530, forming a front cavity for the air conduction speaker 1530. Air-conducted sound waves generated by the air conduction speaker 1530 can propagate in the listening direction through acoustic holes installed in the wall of the front cavity.

[0121] In some embodiments, the vibration direction of the bone conduction speaker 1520 (i.e., the direction in which bone conduction sound waves propagate from the bone conduction speaker 1520) may be perpendicular to the user's skin (indicated by the dashed line 1550), and the central vibration direction of the diaphragm of the air conduction speaker 1530 may be parallel to the user's skin (indicated by the dashed line 1550). In this case, the central vibration direction of the diaphragm of the air conduction speaker 1530 may be substantially perpendicular to the vibration direction of the bone conduction speaker 1520. The vibration of the bone conduction speaker 1520 (or the bone conduction sound waves generated by the bone conduction speaker 1520) has no or little effect on the vibration of the diaphragm of the air conduction speaker 1520, thereby achieving a higher sound effect of the audio output device 1500. Note that the central vibration direction of the diaphragm of the air conduction speaker 1530 does not have to be completely perpendicular to the vibration direction of the bone conduction speaker 1520. For example, the angle between the two directions may be greater or less than 90 degrees (eg, 70 degrees, 80 degrees, 85 degrees, 95 degrees, 100 degrees, 115 degrees, etc.).

[0122] The bone conduction speaker 1520 may be electrically coupled to the bone conduction signal processing circuit 316. The bone conduction speaker 1520 may generate and output bone conduction sound waves within a specific frequency range (e.g., low frequency range, mid-frequency range, high frequency range, mid-low frequency range, mid-high frequency range, etc.) based on a bone conduction control signal generated by the bone conduction signal processing circuit 316. The air conduction speaker 1530 may be electrically coupled to the air conduction signal processing circuit 317. The air conduction speaker 1530 may generate and output air conduction sound waves within the same or a different frequency range as the bone conduction speaker 1520 based on an air conduction control signal generated by the air conduction signal processing circuit 317.

[0123] For example, bone-conducted sound waves may include mid-high frequencies, and air-conducted sound waves may include mid-low frequencies. The mid-low frequency air-conducted sound waves can be supplemented with the mid-high frequency bone-conducted sound waves. The total output of the acoustic output device may cover mid-low and mid-high frequencies. In this case, better sound quality (especially at low frequencies) can be provided, and strong vibrations at low frequencies of bone-conducted speakers can be avoided.

[0124] More detailed information regarding the frequency distribution of bone-conducted and / or air-conducted sound waves can be found elsewhere herein, for example, in Figures 17-21.

[0125] The above description is for illustrative purposes only and is not intended to limit the scope of the present specification. Those skilled in the art may make various changes and modifications based on the description herein. However, these changes and modifications do not depart from the scope of the present specification. For example, the number, position, size, and / or shape of the acoustic holes and decompression holes of the acoustic output device may not be limited to the embodiments shown in the drawings. In some embodiments, the acoustic tube may be coupled to the acoustic hole. In some alternative embodiments, the acoustic tube may be inserted directly into the housing 1510 through the wall. For example, the relative positions of the bone conduction speaker 1520 and the air conduction speaker 1530, the mass, shape, and / or size of the housing 1510, and one or more additional acoustic structures may be modified and optimized according to various needs and are not limited herein. For example, the bone conduction speaker 1520 and the air conduction speaker 1530 may each be housed in two housings.

[0126] FIG. 16 is a schematic diagram of a leakage frequency response curve of an acoustic output device 1500 according to some embodiments of the present disclosure. The air conduction speaker 1530 of the acoustic output device 1500 may be embedded in the sidewall 1512 of the housing 1510. In this case, the mass and rigidity of the sidewall 1512 can be increased, reducing vibration of the housing 1510 and thereby reducing sound leakage from the acoustic output device 1500. Leakage frequency response curves for various conditions of the acoustic output device 1500 can be provided. The horizontal axis may represent sound frequency. The vertical axis may represent the amount of sound leakage from the acoustic output device 1500. As shown in FIG. 16 , a first leakage frequency response curve 1610 is provided under the condition where the acoustic output device 1500 includes only the bone conduction speaker 1520 (omitting the air conduction speaker 1530). A second leakage frequency response curve 1620 is provided, showing sound leakage from the acoustic output device 1500 at different frequencies.

[0127] As can be estimated based on the leakage frequency response curves 1610 and 1620, within a certain frequency range (e.g., 150 Hz to 10,000 Hz), the sound leakage of the audio output device 1500 is smaller than the sound leakage when the audio output device includes only a bone conduction speaker.

[0128] 17 to 21 are schematic diagrams of frequency response characteristic curves of an acoustic output device according to some embodiments of the present disclosure. An acoustic output device (e.g., acoustic output device 600, 700, 800, 1100, 1200, or 1500) may include a bone conduction speaker and an air conduction speaker. The bone conduction speaker and the air conduction speaker may be independent of each other. The bone conduction speaker and the air conduction speaker may generate sound waves of different frequencies (e.g., mid-low frequency, mid-high frequency, etc.). The sound waves of different frequencies may be complementary to each other to achieve a specific output effect.

[0129] As shown in FIG. 17 , bone-conducted sound waves generated by a bone-conducted speaker and air-conducted sound waves generated by an air-conducted speaker may include different frequencies. In some embodiments, bone-conducted sound waves may include mid-high frequencies (shown by short dashed lines in FIG. 17 ), and air-conducted sound waves may include mid-low frequencies (shown by dashed lines in FIG. 17 ). Air-conducted sound waves including mid-low frequencies (i.e., mid-low frequency sound) can propagate through the air to the ears of a user wearing the acoustic output device, while bone-conducted sound waves including mid-high frequencies (i.e., mid-high frequency sound) can propagate to the user through the user's bones. The mid-low frequency sound can be complementary to the mid-high frequency sound. The total output of the acoustic output device (shown by a solid line in FIG. 17 ) may cover both mid-low and mid-high frequencies. This can provide better sound quality (especially at low frequencies) and avoid strong vibrations at low frequencies of the bone-conducted speaker.

[0130] Generally, human hearing is sensitive to mid- to high-frequency sounds, while human touch is sensitive to low-frequency sounds. In some embodiments, bone-conducted sound waves may include mid- to low-frequency sounds (shown by dashed lines in FIG. 17 ), and air-conducted sound waves may include mid- to high-frequency sounds (shown by short dashed lines in FIG. 17 ). In this case, since the user is sensitive to mid- to low-frequency bone-conducted sound waves and / or mid- to high-frequency air-conducted sound waves, the audio output device may provide a notification or warning to the user via a bone-conducted speaker and / or an air-conducted speaker. Note that the mid- to high-frequency sounds may overlap. For example, the maximum frequency of the mid- to low-frequency sounds (e.g., the frequency corresponding to the half-power point of the mid-to-low frequency curve) may be greater than the minimum frequency of the mid-to high-frequency sounds (e.g., the frequency corresponding to the half-power point of the mid-to high frequency curve). In some alternative embodiments, the mid- to high-frequency sounds may not overlap.

[0131] In some embodiments, bone-conducted sound waves and air-conducted sound waves may include the same frequency. As shown in FIG. 18 , the bone-conducted speaker and the air-conducted speaker of the acoustic output device may generate sound waves of different frequencies (e.g., frequencies within a wide frequency range (also referred to as a wide frequency range, shown by the short dashed line in FIG. 18 ) or frequencies within a narrow frequency range (also referred to as a narrow frequency range, shown by the dashed line in FIG. 18 )). Sound waves of different frequencies may be complementary to achieve a specific output effect. In some embodiments, bone-conducted sound waves and air-conducted sound waves may include the same frequency within the mid-low frequency range. In this case, the total output of sound waves within the mid-low frequency range of the acoustic output device (shown by the solid line in FIG. 18 ) may be greater than that within the mid-high frequency range. In other words, the total output of the acoustic output device may be increased within the mid-low frequency range. Because the human hearing threshold is high in the low-mid frequency range but low in the high-mid frequency range (i.e., humans are more sensitive to mid-high frequency sounds), increasing the sound wave output in the low-mid frequency range can compensate for the effect of the hearing threshold, thereby equalizing the different frequency sounds that humans hear.

[0132] In some embodiments, the air-conducted sound waves may include low-mid frequencies, and the bone-conducted sound waves may include frequencies within a wider frequency range (wide frequency range) than the air-conducted sound waves. Therefore, the output of low-mid frequencies can be increased, improving sound quality. Strong vibrations at low-mid frequencies can also be avoided, thereby improving user comfort and hearing safety. In some embodiments, the bone-conducted sound waves may include low-mid frequencies, and the air-conducted sound waves may include frequencies within a wider frequency range (wide frequency range) than the bone-conducted sound waves. By adding moderate vibrations at low-mid frequencies, the user can be provided with a tactile sensation along with an auditory sensation, thereby enriching the user's audio experience.

[0133] As shown in FIG. 19 , bone-conducted sound waves and air-conducted sound waves may include the same frequencies within the mid-high frequency range to increase the volume of mid-high frequencies or reduce mid-high frequency sound leakage. In some embodiments, the air-conducted sound waves may include mid-high frequencies (e.g., mid-high frequencies in opposite phase as shown by the dashed line in FIG. 19 ), and the bone-conducted sound waves may include frequencies within a wider frequency range (wide frequency range) than the air-conducted sound waves. Due to the principle of opposite phase cancellation, the air-conducted sound waves can reduce or eliminate mid-high frequency sound leakage of a bone-conducted speaker (e.g., the leakage of a bone-conducted speaker shown by the short dashed line in FIG. 19 ). In this case, the overall sound leakage of the audio output device (shown by the solid line in FIG. 19 ) can be reduced at mid-high frequencies.

[0134] As shown in FIG. 20, bone-conducted sound waves may include mid- to high-frequency sounds (e.g., a narrow range of frequencies indicated by the dashed line in FIG. 20), and air-conducted sound waves may include frequencies within a wider frequency range than bone-conducted sound waves (e.g., a wider range of frequencies indicated by the short dashed line in FIG. 20), thereby increasing the total output of mid- to high-frequency sound waves (indicated by the solid line in FIG. 20) (e.g., increasing the volume in the mid- to high-frequency range of the acoustic output device).

[0135] In practical applications, in earphones equipped with air conduction speakers, the bone conduction sound waves generated by the bone conduction speaker can supplement the mid- and high-frequency sounds of the air conduction speaker. Because the vibration amplitude of the bone conduction speaker is large in the low-frequency range, the user's face experiences a strong vibration sensation, resulting in a poor user experience. To reduce or eliminate the vibration, the low-frequency sounds of the bone conduction speaker may be suppressed (e.g., by a frequency divider or crossover), which results in a sharp drop in the low frequencies of the bone conduction speaker and a deterioration in sound quality. However, the air conduction speaker may also be used to supplement the low frequencies. Specifically, the audio output device outputs low-frequency sounds through the air conduction speaker and mid- and / or high-frequency sounds through the bone conduction speaker, allowing the user to enjoy a balanced audio experience.

[0136] As shown in FIG. 21 , the bone conduction speaker may output high-frequency sounds (indicated by short dashed lines in FIG. 21 ), and the air conduction speaker may output low-frequency sounds (indicated by dashed lines in FIG. 21 ). By outputting high-frequency and low-frequency sounds, the sound output device can improve user comfort and maintain acoustic effects. In some embodiments, high frequencies may refer to frequency ranges greater than 300 Hz, 1000 Hz, 10 kHz, etc. Correspondingly, low frequencies may refer to frequency ranges less than 250 Hz, 500 Hz, 1 kHz, etc.

[0137] FIG. 22 is a schematic diagram of a vibration displacement spectrum of a bone conduction speaker according to some embodiments of the present disclosure. The vibration displacement of the bone conduction speaker at different frequencies can be measured using a laser vibrometer. As shown in FIG. 22, the resonance peak of the bone conduction speaker is approximately 180 Hz. The vibration amplitude of the bone conduction speaker increases rapidly from approximately 100 Hz to 250 Hz, which may be a vibration-sensitive region. In some embodiments, the frequency division point of the bone conduction speaker and the air conduction speaker may be set to approximately 250 Hz. Therefore, the air conduction speaker can generate air-conducted sound waves mainly with frequencies below 250 Hz, while the bone conduction speaker can generate bone-conducted sound waves mainly with frequencies above 250 Hz. As a result, the vibration amplitude of the bone conduction speaker can be maintained within a relatively small range, which effectively weakens the vibration sensation on the user's face and equalizes the sound effect.

[0138] Although the basic concepts have been described above, it will be apparent to those skilled in the art after reading this application that the above disclosure of the invention has been presented by way of example only and is not intended to limit the present specification. Although not expressly described herein, those skilled in the art may make various changes, improvements, and modifications to the present specification. These changes, improvements, and modifications are suggested by this specification and are therefore within the spirit and scope of the illustrative embodiments of the present specification.

[0139] Furthermore, certain terms are used herein to describe embodiments herein. For example, "one embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment herein. Therefore, it is emphasized and understood that references to "one embodiment" or "one embodiment" or "one alternative embodiment" more than once in various parts of this specification do not necessarily all refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments herein may be combined as appropriate.

[0140] Moreover, as will be appreciated by those skilled in the art, each aspect of the present specification may be illustrated and described in several patentable classes or contexts, including any new and useful process, machine, manufacture, or combination of matter, or any new and useful improvement thereto. Accordingly, each aspect of the present specification may be implemented entirely in hardware, entirely in software (including firmware, resident software, microcode, etc.), or a combination of software and hardware, where these implementations are generally referred to herein as "modules," "units," "assemblies," "apparatus," or "systems." Furthermore, each aspect of the present specification may take the form of a computer program product embodied in one or more computer-readable medium(s) containing computer-readable program code.

[0141] The computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave for carrying computer program code. Such propagated signals may include various forms, such as electromagnetic signals, optical signals, or a suitable combination. The computer-readable signal medium may be any computer-readable medium other than a computer-readable storage medium, which can be coupled to an instruction execution system, apparatus, or device to realize communication, propagation, or transmission of a program used therein. The program code on the computer-readable signal medium may be propagated in any suitable medium, including wireless, cable, fiber optic cable, RF, etc., or any combination of the above media.

[0142] Computer program code for carrying out operations of each aspect of the present disclosure may be coded in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB.NET, Python, etc.; the "C" programming language; traditional procedural programming languages ​​such as Visual Basic, Fortran 2003, Perl, COBOL 2002, PHP, ABAP; dynamic programming languages ​​such as Python, Ruby, and Groovy; or other programming languages. The program code may run entirely on the user's computer, on the user's computer as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer may be connected to the user computer via any type of network (including a local area network (LAN) or a wide area network (WAN)), may be connected to an external computer (e.g., using a network service provider's network), may be in a cloud computing environment, or may be provided as a service, e.g., Software as a Service (SaaS).

[0143] Furthermore, unless expressly stated in the claims, the enumerated order, use of alphanumeric characters, or use of other designations of processing elements or sequences described herein does not limit the order of the procedures and methods herein. While the above disclosure has set forth through various examples what are presently believed to be some useful embodiments of the invention, it will be understood that such details are for the purpose of illustration only, and that the appended claims are not limited to the disclosed embodiments, but on the contrary, are intended to cover all modifications and equivalent combinations within the spirit and scope of the embodiments herein. For example, the various assemblies described above may be implemented by hardware devices, or may be implemented as software-only solutions, e.g., by installation on existing servers or mobile devices.

[0144] Similarly, in the foregoing description of embodiments herein, it will be understood that various features may be grouped together in a single embodiment, drawing, or description for the purpose of simplifying the description and facilitating an understanding of one or more inventive embodiments. However, this method herein should not be interpreted as reflecting an intention that the claimed subject matter requires more features than are expressly recited in each claim. Rather, claimed subject matter may include less than all features of a single foregoing disclosed embodiment. [Explanation of symbols]

[0145] 130, 300, 305, 500, 600, 700, 800, 1110, 1200, 1500 Sound output device 321, 326, 500, 630, 730, 830, 1120, 1220, 1520 Bone conduction speaker 322, 327, 550, 640, 740, 840, 1130, 1230, 1530 Air conduction speakers 520, 560, 810, 1110, 1210, 1510 Housing 610, 710 First housing 620, 720 Second housing 510 Vibration Assembly 511 Magnetic Circuit System 512 Diaphragm 513 Coil 551 diaphragm 552 Drive Unit 570, 723, 822, 1114, 1214 acoustic holes 622 First Acoustic Hole 623 Second Acoustic Hole

Claims

1. a bone conduction speaker configured to generate bone conduction sound waves; an air conduction speaker configured to generate air conduction sound waves, the air conduction speaker including a diaphragm and a driver; at least one housing configured to house the bone conduction speaker and the air conduction speaker; The air conduction speaker is independent of the bone conduction speaker, the housing cavity is divided by the vibrating membrane into two portions including a front cavity and a rear cavity; the front cavity is located on a side of the diaphragm away from the driver, the rear cavity is located on a side of the driver away from the diaphragm, and the bone conduction speaker is disposed in the rear cavity; At least one acoustic hole is provided in the wall of the front cavity of the housing, and a decompression hole is provided in the wall of the rear cavity of the housing; a total output of the acoustic output device covers a mid-low frequency range mainly derived from the air-conducted sound waves and a mid-high frequency range mainly derived from the bone-conducted sound waves; An acoustic output device, wherein the angle formed between the vibration direction of the bone conduction speaker and the central vibration direction of the vibrating diaphragm of the air conduction speaker is greater than or equal to 70 degrees and less than or equal to 115 degrees.

2. The acoustic output device of claim 1 , wherein the air-conducted sound waves include low-to-mid frequencies, and the bone-conducted sound waves include frequencies within a wider frequency range than the frequencies of the air-conducted sound waves.

3. The acoustic output device of claim 1 , wherein the bone-conducted sound waves include low and mid-frequencies, and the air-conducted sound waves include frequencies within a wider frequency range than the frequencies of the bone-conducted sound waves.

4. The acoustic output device according to claim 1 , wherein the air-conducted sound waves include mid- to high-frequency waves, and the bone-conducted sound waves include frequencies within a wider frequency range than the frequencies of the air-conducted sound waves.

5. The acoustic output device according to claim 1 , wherein the bone-conducted sound waves include mid- to high-frequency waves, and the air-conducted sound waves include frequencies within a wider frequency range than the frequencies of the bone-conducted sound waves.

6. The bone conduction speaker includes a vibration assembly, the vibration assembly comprising: a magnetic circuit system configured to generate a magnetic field; a diaphragm connected to the at least one housing; and one or more coils connected to the diaphragm, the coils vibrating in the magnetic field and driving the diaphragm to vibrate and generate the bone-conducted sound waves.

7. The sound output device according to claim 1 , wherein the decompression hole is provided with a sound-adjusting mesh.

8. The sound output device according to claim 1 , wherein the air conduction speaker is installed adjacent to the bone conduction speaker.

9. The sound output device according to claim 1 , wherein the air conduction speaker and the bone conduction speaker are stacked.

10. The sound output device according to claim 1 , wherein the acoustic hole is a through-hole that propagates the air-conducted sound waves to the outside of the housing.

11. The acoustic output device according to claim 1 , wherein the pressure reduction hole is a through-hole that helps to balance pressure between the housing and the outside.

12. The acoustic output device of claim 1 , wherein the bone-conducted sound waves and the air-conducted sound waves have the same frequency and opposite phase within a mid-to-high frequency range.

13. 12. The acoustic output device of claim 1, further comprising a beam forming module configured to form an acoustic beam of the bone-conducted sound waves and / or the air-conducted sound waves, the acoustic beam propagating in a specific direction to achieve a maximum sound pressure level in the vicinity of a human ear.

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